Rising Tides and Retirement: The Aggregate and Distributional Effects of Differential Wage Growth on Social Security

WP#2009-7

Abstract

Recent growth in wage inequality has important implications for Social Security solvency and the distribution of benefits. Because only earnings below the taxable maximum are subject to Social Security payroll taxes, wage growth that is concentrated among very high earners will generate lower tax receipts than wage growth that is more evenly distributed. The progressivity of the Social Security benefit formula increases benefit payouts when the share of workers with low wages grows. This study uses a dynamic microsimulation model to examine the aggregate and distributional consequences of alternative scenarios about the distribution of future wage growth among workers. We find fairly marked changes in projected Social Security benefit distributions, poverty, and long-term financing status with relatively modest changes in assumptions about wage differentials.